My trials, tribulation and progress in designing and building a handcycle, at home, out of carbon fiber.

Wednesday, January 25, 2012

A handcycle pumping iron... Putting weights on the bike

OK, now the scary part... But I gotta do it. I am going to add weight to the bike to see if it creaks and cracks -- but especially to see how much deflection there is. I weigh in at 193 lbs. I will be adding up to 200 lbs of iron to the bike. I should probably add about 400 lbs -- but I am not quite ready for that (mentally speaking that is).

I have used the fast-hardener on most of the bike and therefore, can expect the bike to be near full strength.

Here we go... Got some weights and a tape measure...

90mm off the floor with 0 lbs. of weight applied:

...Drop of 10 mm at 70 lbs added
...Drop of 15 mm at 120 lbs added

...Drop of 25 mm at 160 lbs added
...Drop of 35mm at 200 lbs added

I have not completed any calculation nor have any real expectations of what I should have expected relative to deflection. After hitting 200 pounds, the whole bike shifted and the weights fell off the bike. There was no damage to the bike and it sprung right back to the original 0 lbs./90mm clearance. That is a somewhat good sign I guess -- at least better than the alternative!